O-Mac MF 2500 Manual page 55

securely using the wrench (Fig. 9).
Never work with the chain loose as it can
be hazardous if the chain slips out of the bar
guides.
IMPORTANT During the first period of use
it must be checked more frequently due to
settling of the chain.
6.1.4 Preparing the machine before starting
work
• Anti-freeze device
When using the chainsaw at temperatures
under +5°C, it is necessary to change the anti-
freeze de-vice settings before starting the
machine to prevent ice from forming inside
the carburettor, which will result in a loss in
engine power or erratic engine performance.
The machine is equipped with an air vent
hatch on the cylinder lid, to allow warm air
flow to the engine.
In normal operating conditions (temperatures
above +5°C), use the machine in standard
operat-ing mode, i.e. using factory default
settings.
To switch from "Normal " mode to "Anti-freeze
"mode (and vice versa):
1. stop the machine (par. 6.6);
2. remove the air filter cover and the air filter
(par. 8.2);
3.a on models SP386, SP 426:
– remove the anti-freeze cap from its
housing to the right of the cylinder cover
(Fig. 14.A);
– Turn the anti-freeze cap so that the
«SNOW» symbol is facing downwards to
leave the air vent hatch open (Fig. 14.B);
3.b on models SP466, SP 526:
– unscrew the screws which secure
the cylinder cover in place (Fig. 15.A)
(2 screws inside and one outside) and
remove the cylinder cover. (Fig. 15.B);
– remove the anti-freeze cap from its
housing (Fig. 16.A), in the centre and at
the back of the cylinder cover (Fig. 16.B);
– Turn the anti- freeze cap so that the
«SNOW» symbol is facing downwards
(Fig. 17.A) to leave the air vent hatch open
(Fig. 17.B);
– remount the cylinder cover.
4. remount the air filter cover and the relative
cover (par. 8.2).
NOTE If the machine is used in anti-freeze
mode at temperatures above +5°C, this may
cause difficulties when starting the engine
and during use due to the incorrect engine
speed. Always check that the machine is
switched to standard mode (anti-freeze cap
with the «SUN» symbol facing sideways and
the air vent hatch closed) if there is no danger
of ice forming.
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